#______________________________________________________________________________
class RandomVariable(object):
    """ The base class for all random variables - discrete or continuous. """
    def __init__(self, name='?'):
        self.name = name.strip()

#______________________________________________________________________________
class DiscreteRandomVariable(RandomVariable):
    """ The base class for all discrete random variables. """
    pass

#______________________________________________________________________________
class ContinuousRandomVariable(RandomVariable):
    """ The base class for all continuous random variables. """
    pass

#______________________________________________________________________________
class NormalDistribution(ContinuousRandomVariable):
    """ An n-dimensional normal distribution.  If the mean and covariance
        matrix are omitted, it defaults to the standard, 1-dimensional
        normal distribution. """
    def __init__(self, mean=[0.0], covariance=[[1.0]]):
        pass
